Reeling-off silk cocoons



Patented Feb. 28, 193 3 I i UNITED STATES: TE TIY CFFICEIY BERNARD LOEWE, or ITALY REELING-OFF SILK cocoons No Drawing. Application filed December 1 1, 1930, Serial No. 501,661, and in Germany June 10, 192% The invention relates to improvements in such a way that the threads obtained-from reeling-off silk cocoons and has for its object the cocoons acquire a. greater resistance for a treatment of the cocoons whereby the reelthe subsequent treatment incaustic alkali soing-off of the same is facilitated and the silk lutions; the said weak: alkali solutions also threads obtained therefrom rendered more precipitate the lime iofvthe moreor lesshard resistant and better adapted to subsequent Water employed for the reeling-off of the silk use, g p threads andthereby preserve the latter from It has already been proposed to treat cothe undesired and detrimental influence of ccons preliminary to their reeling-01f by ,imthe llme; the filaments obtained from such V. 1a mersion in a bath consisting of a solution of threads are consequently of superior quality. 60 alkalis or alkaline earths, which treatment The cocoons treated :by immersion in'the may be preceded by a treatment'in a bath convaforesaid weak ammonia or alkaline solusisting of a solution of neutral, alkaline or tlons to wh ch are added or. notadded salts acid salts, mineral or organic acidsoroils and f the klnd referred to, are however not to ubsequently reel-01f in cold waterthe coadapted to be-reeled-oif in cold water but are coo-n threads from which the bast has not been only rendered capable of being so by th removed by the "said treatments. sequent treatment in caustic alkali solutions. It, has now been discovered that a prelim} TlllS latter treatment when: carried; out inary treatment of cocoons in a bath consist- M 16 auses the cocoons to beeasily reeled- 2c ing of a very weak solution of ammonia or oil; in coldwater, but the silk filaments obof very weak alkaline solutions, succeeded tamed, e y are not y because b a t t t, f such t t d 309001 3 when the Sllk is stored for a longer period, with caustic alkali "in solution'achieves eX e fi 'O n Of csilk is attacked even when ll t lt j th r li 'ofi. Th v y very .weak caustlc alkali solutions have been 2 weak'alkaline solutions above referred to may mp y dbe solutions of the aliphatic amino 001D The trath16nb0ith6 00000118 r ng o pounds, for instance methylamimethylamin, the present invention may be carried out for or the quarternary ammonium bases such as Instance as follows: tetramethylammonium with or without the The cocoons are" first immersed in a Weak 30 simultaneous addition of one or more organic kah ll g l i n Of-ammonia or of oriinorganic salts, especially those of ammof h compounds to Whlch' y eadded if nium or sodium such as ammonium acetate, deslred a solution. of one or more salts as sodium acetate, ammonium formate, sodium p cfl beforev formate, ammoniumv ulphate, sodium sul- It ls'lmmaterlal and unimportant for the v phate and the like. g I result vobtained, whether a solution of am- Concentrated solutions of ammonia as well monla Solution f min ompounds is as concentrated solutions of alkali salts or Chosen, n y on al T ISOIIS Will have alkaline reacting solutions of salts act at a i be; C01}S1dered 1n 'Qh e t mthe Same temperature of- 30 C. and below on cocoons lS haddltloll Q .11 1g m IQ 01" at t remove th h t th e f d tQ pr i it t game or mineral salts wh ch ElCll'll-li catalyit; this action causes a defective reeling-off i g ECOIIOIIHG reasons Will also he of the cocoons in cold water and the reeledlve the P Y BH f One or the off silk has "not sufficient coherence on acother of more Of these Saltscount of the bast having been partially resolutlons'of the-aforesaid kind may have 45 moved. 1 -j f the compositions as thefollowing ex- 'Very weakrsolutions of ammonia as well amples, the proportion'sof the constituents as very weak alkaline solutions with or withof the solutions may vary somewhat but in out the addition of salts of the aforesaid any case the solutions-{must be weak solukind however do not remove the ba'st from tions not exceeding 0.5% and preferably of 50 the cocoons but form compounds with it in considerable lower concentration. 793

Example 1.-0.5% ammonia or 0.6% methylamin a. s. 0.,

Example 2.-0.6% ammonia, 0.6% ammonium acetate, or sodium acetate,

Example 2'.0.5% methylamin, 0.5% ammonium formate or sodium formate,

Example 3.0.6% ammonia, 0.5% ammonium formats or ammonium acetate, 05% sodium formats, or sodium acetate,

Example 3.-0.5% tetramethylammonium-' hydroxide, 0.5% sodium-formate, 0.590

ammonium acetate a. s. o.

. on account of fermentation processes which take place in the baths, the bad smell renderin the renewal of the bath advisable, although the bath is still effective. Beforedev-eloping the bad smell, the bath, if desired, may be brought to its original concentration when it shows that the subsequently used caustic alkali bath under the same conditions: concentration, temperature and period of action, decreases in effectiveness. This decreasing is noticed when reeling-off the threads in cold Water in that the reeling ofl does no longer proceed as easily and evenly as before.

I After the cocoons have been treated in the first bath referred to, they are immersed into a bath consisting of a caustic alkali solution of 2 B. or less at a temperature of about their durability. with acid the cocoons are not adapted to be reeled ofi'.

30 C. or less for about 10 minutes, whereupon they are reeled-off in fountain water at a temperature of 30 C. or less, that is at room temperature.

Between the first treatmentwitha solution of ammonia or any other. alkaline solution with or without the addition of salts and the second treatment by means of a causticalkali solution, a treatment with a weak mineral or organic acid, i. e. of formic acid or hydrochloric acid may he inserted to neutralize free alkali. This treatment with a weak acid assists in loosening the end of the silk threads and increases After the said treatment The treatment in the" caustic alkali solucentration. For instance, the cocoons are first immersed into a b-athof 0.5-0.9 Bi'of sodiumor potassium hydroxide for 10 to'60 minutes and subsequently into asjolut-ion of .the natureof cocoons to be treated.

Whether the said treatment with caustic alkali solution is carried out in one bath or in stages, that is in two baths of different strength depends on the hardness and the ageof the cocoons; in general it is sufficient to have the cocoons treated in a single stage; however when so-called Doppi (double cocoons) have to be reeled. off or'when the cocoons are, old or when the killing of the pupae and drying was carried outat temperatures higher than -85 C. it is preferred to work in. two stages and to first use the weaker and subsequently the stronger bath. The reverse procedure, that is, to use first the stronger andafterwards the Weaker bathwill be adopted if cocoons which have not been dried uniformly, have to be rendered uniform, that is if such cocoons have to be equalized for reeling purposes. Under normal conditions the preliminary use of the weaker bath will be preferred because when being treated for a longer time 111 a stronger bath, the silk layers of the cocoons are loosened and the reeling-off does not pro ceed so easily and will result in a silk which is not soclean as otherwise. I

In order to increase the coherence of the reeled-off filament, which consists of two or more cocoon threads, there may be added to the caustic alkali solution respectively, if this solution is used in two stages, to either or to both of the solutions of different concentration an emulsion consisting. of about 3 g. bicarbonate of soda and 40 g. sulphonated castor oil. If desired g. sugar (glucose) may be added to this emulsion for each litres of the caustic alkaline solution. The proportion of the constituents of the said emulsion and of the added sugar may vary according to the nature of the cocoons to be treated. It is preferred to add the emulsion to the weaker caustic alkali solution in case of using diiferentlyconcentrated solutions.

In order to increase the coherence and the elasticity ofthe' reeled-off silk filaments still to a higher degree than is possibleby the addition of the aforesaid emulsion, a weak solution of protein substances, such as eggalbumin, fish-glue and the like may be added in a proportion. of 0.2-0.3 g. for each kg. of cocoons either to the preliminary alkaline bath or to the subsequent caustic alkali bath or to both baths with or without sulphonated castor oil and glycerine.

, The weaker bath of caustic alkali solution may be continuously used for a long time and from time to time it is brought .to the original concentration in order to maintain the time of immersion of the cocoons as constant as possible. If the bath decreases in concentration the time of immersion of the cocoons shouldaccordingly be prolonged.

It is recommendable to prove the concentrationand temperature of the stronger bath at intervals, say at the end of each days work and to regenerate it to the original concentration in order to maintain equal working conditions. When the baths get dirty on account of the dust etc. of the cocoons, a complete removal of the baths should be carried out.

After the treatment in the last bath the cocoons should not be washed in a' solution of an acid nor reeled-off in water of acid reaction, because otherwise the bast ofthe cocoons, which has been rendered soft and sticky would coagulate and the reeling-off would meet with difficulties; the silk reeledofi furthermore would not have suiiicient coherence.

In order to remove or render ineffective the free alkali or caustic alkali without washingthe treated cocoons with acid but in reeling them off in clean water, it is advisable to remove by vacuum the liquids absorbed by the cocoons during the enumerated treatments in the baths prior to the reeling-off. This removal has the further advantage that the cocoon is made lighter in weight and that the elasticity of the finished thread is increased.

The process according to the invention may for the instance be carried out as follows:

5 kg. of cocoons are immersed during five hours in one or the other of the following a baths consisting of ammonium formate.

Thereupon the cocoons are treated during 10 minutes in a bath consisting of 100' litres sodiumhydroxide of 1.2? Be. at a vacuum of 25 to mm. mercury, and then reeled-off in cold water.

The presence of vacuum or pressure during the treatment in the baths assists the uniform action of the baths unto all layers of the cocoons to their interior and renders them also more adapted to uniformly take up the water in the spinning or reeling-off basin. By the action of vacuum or pressure the 100 litres water, cm ammonia of 28 B. 50 g. sodium acetate and 50 g.

immersion of the cocoons into waterduring I water and 60 cm hydrochloric acid of, a concentration of 37% or in asolution of litr-es water and 50 cm acetic acid of aconcentration'of 99-10070. 7

As aforementioned the treatment in the caustic alkali bath may be carried through in two solutions of different concentration; in this connection it may be proceeded with in the following manner. 'The cocoons coming from the'alkaline bath are consecutively in troduced in small batches of 50-200 g. in a solution of about 5 litres sodiumhydroxide of O.9 .B. containcdfin small autoclaves and treated therein for aboutl5 minutes, whereupon they are treated i'na second solution of sodiumhydroxide of 12 B. underva'cuum of about 25-50 mm. mercury for two or three minutes. As an alternative, the cacoons may first be introduced into the stronger solution and subsequently into the weaker solution.

After the treatment just described, the cocoons are reeled off in cold water.

Examples of emulsions adapted to increase the coherence of the thread are the following:

57 cm water I "3 g.- bicarbonate of soda and 40 cmsulphonated castor oil' a Y 56% cm water sugar. a 3 g. bicarbonate of soda and 40 g, sulphonated castor-oih The above indicated quantities of emulsions are suitable for and are added to each 100 litres sodiumhydroiiide.

When introducing in the alkaline baths for each 5 kg. cocoons for instance a solution consisting of i r 15 g. 'fish glue 40 cm ammonia 28 B; 45 cm water I or in the caustic alkaline baths a solution consisting of .15 g. fish glue Q i 10 cm sodiumhydroxide 35 B.

V 7 5 cm water in the proportion of 100 cm per 100 litres of the treating bath, a superior coherence of the threads and filaments respectively is secured.

The composition of the above solution may vary in a multiple way for example solutions consisting of a oil and water, and/or 40 cm ammonia28 Be.

10 cm sulphonated castor-oil Y 35 cm water 15 g. fish-glue 40 cm ammonia 28 B.

10 cm sulphonated 'castor-oil i 1 cm glycerin and 34 cm water solution is to be replaced by 10 cm of hy-V droxide of sodium or potassium of 35 B.

A superior coherence is also secured when adding to the water in the reeling-0E basin a solution of protein substances,for example a solution comprising 5 g. fish-glue and 200 cm sodiumhydroxide of 1 B. The above quantityof protein solution is suiiicient for 1520 litres water at room temperature.

WVhat I claim as my invention and desire to secure by Letters Patent is: 7

1. A methodof treating silk worm cocoons consisting in first treating the cocoons in a preliminary bath of a weak solution of a basic ammonium compound of a concentration below 0.5% continuing this preliminary bath until this solution has penetrated all layers of silk of the cocoons and then treating them with a caustic alkali solution of a concentration up to 2 B. at room temperature for at least a minute, then reeling off the cocoons in water at room temperature.

2. A method of treating silk worm cocoons consistingin first treating the cocoons in a preliminary bath of a watery ,colution of an alkaline ammonium compound of a concentration below 0.5% to which is added at least one salt adapted to act asa catalytic agent, continuing this preliminary bath until this solution has penetrated all layers of silk of the cocoons and then treating them with a causitc alkali solution of a concentration up to 2 B. at room temperature for at least a minute, then reeling 011' the cocoons in water at room temperature. V

3. A method of treating silk worm cocoons consisting in first treating the cocoons in a preliminary bath of a weak solution of a basic ammonium compound of a concentration below 0.5% continuing this preliminary bath until this solution has penetrated all layers of silkof the cocoons then washing them with a weak acid solution adapted to neutralize the alkali not bound to the bast of the cocoons, then treating them with a caustic alkali solution of a concentration up to 2" B. at room temperature for at least a minute, then reeling ofi' the cocoons in water at room temperature. I

4; A method oftreating silk Worm cocoons consisting in first treating the cocoons in a preliminary bath of a Watery solution otan alkaline ammonium compound of a concentration below 0.5%, to which is added at least one salt adapted to act as catalytic agent, continuing this, preliminary treatment untilthe bath has penetrated all layers of silk of the cocoons, then washing them with a diluted acid adapted to neutralize the alkali not bound to the bast ofthe cocoons, then treating the washed cocoons with a caustic alkali solution of a concentration up to 2 B. at room temperature for at least a minute, then reeling'ofi' the cocoons in water at room temperature.

5. A method of treating silk worm cocoons consisting in first treating the cocoons in a preliminary bath of a watery solution of an alkalineammonium compound of a concentration below 0.5%.continuing this preliminary bath until this solution has penetrated all layers of silk of the cocoons and treating them at room temperature in a caustic alkali solution, which is subdivided into a plurality of baths, each of the said baths differing in 1 concentration from the, others'and none of them surpassing a concentration of 2 B. for a total period of time of at least a minute, then reeling off the cocoons in water of room temperature. 1

6; A method of treating silk worm cocoons consisting in first treating the cocoons in a preliminary bath of a watery solution of an alkaline ammonium compound of a concentration below 0.5% to which is added at least one salt adapted to act as a catalytic agent, continuing this preliminary treatment. until the bath has penetrated all layers of silk of thecocoons,then treating them at room temperature in a caustic alkali solution, which is subdivided into a plurality of baths, each of said baths differing in concentration from the others and none of them surpassing a concentration of 2 B. fora total period of time of atleast a minute, then reeling off the cocoons inwater or room temperature.

7. A method of treating silk worm cocoons consisting in first treating the cocoons in a preliminary bath of a watery solution of an alkaline ammonium compound of a concentration below 0.5% continuing this preliminary bath until this solution has penetrated all layers of silk of the cocoons, then washing them with a weak acid solution adapted to neutralize the alkali not bound to the bast of the cocoons, then t-reatin them at room temperature in a caustic alkali solution, which is subdivided into a plurality of baths, each of the said baths diii'ering in concentration from the others and none of them surpassing a contime of at least a minute, then reeling oil the cocoons in water of room temperature.

8. A method of treating silk worm cocoons consisting in first treating the cocoons in a preliminary bath of a watery solution of an alkaline ammonium compound of a concentration below 0.5%, to which is added at least one salt adapted to act as catalytic agent, continuing this preliminary treatment until the bath has penetrated all layers of silk of the cocoons, then washing them with a diluted acid adapted to neutralize the alkali not bound to thebast of the cocoons, then treating them at room temperature in a caustic alkali solution, which is subdivided into a plurality of baths, each of the said baths differing in concentration from the others and none of them surpassing a concentration of 2 B. for a total period of time of at least a minute, then reeling oil the cocoons in Water of room temperature.

9. A method of treating silk worm cocoons as claimed in claim 1 in which the caustic; alkali solution contains at least a substance adapted to increase the coherence of the silk filaments.

10. A method of treating silk worm cocoons as claimed in claim 1, in which at least one of the treating liquids including the water for reeling up the threads contains substances adapted to increase the elasticity and coherence of the silk filaments of the threads.

11. A method of treating silk worm cocoons V as claimed in claim 1, in which the treatment in the solutions is conducted in the presence of a pressure other than atmospheric pressure.

12. A method as claimed in claim 5 in which at least one of the caustic alkali solution baths contains substances adapted to increase the coherence of the, silk filaments.

13. A method as claimed in claim 5 in which at least one of: the treating liquids including the water for reeling up the threads contains substances adapted to increase the coherence of the silk filaments.

14. A method as claimed in claim 5 in which the treatment in the solutions is conducted in' the presence of a pressure other than atmospheric pressure.

15. A method as claimed in claim 1 in which the cocoons after their last chemical treatment and prior to their reeling oil are sub.- jected to the action of Vacuum to free them from absorbed solutions.

In testimony whereof I aflix my signature.

BERNARD LOEWE. 

